Improvement in calipers



H. c. WIGHT.

Caliper.

v No. 205,225. Patented June 25,1878.

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PATENT OFFICE.

HIRAM C. WIGHT, OFWOROESTER, MASSACHUSETTS.

IMPROVEMENT-IN CALIPERS.

Specification forming part of Letters Patent N0.'205,225, dated June 25,1878 application filed May 16, 1878.

To all whom it may concern:-

Be it known that I, HIRAM O. WIGHT, of the city and county of Worcester,and Commonwealth of Massachusetts, have invented certain new and usefulImprovements in Calipers; and I do hereby declare that the following isafull, clear, and exact description of the same, reference being had tothe accompanying drawings, forming a part of this specification, and inwhich- Figure 1 represents a top or back view of my improved calipers.Fig. 2 represents a side view of the same. Fig. 3 represents a frontedge view of the device. Fig. 4 represents a vertical centrallongitudinal section through the calipers, taken on line A B, Fig. 1;and Fig. 5 represents a vertical transverse section through the same,taken on line 0 D, Fig. 2, looking in the direction indicated by arrowin the same figure.

The nature of my invention consists in slidi n g the movable jaw of thecalipers back and forth in a slot formed or cut out in the bar uponwhich is formed the other jaw; also, in the construction of said movablejaw, as will be hereinafter more fully described.

To enable those skilled in the art to which my invention belongs to makeand use the same, I will proceed to describe it more in detail.

In the drawings, the part marked E represents a rectangular bar, oneend, F, of which is curved, and constitutes the stationary jaw of thecalipers. The movable jaw G, which is also curved to correspond to jawF, slides back and forth in a slot, H, formed in said bar E, being heldin place by means of an adjusting and set screw, 1.

The edge of movable jaw G is cut away to form a flange, J, (see Fig. 5of the drawings,) which fits into slot H, and the sides a and b, formingthe sides of said slot, bear upon shoulders a" and b of jaw G, thuspreventing said jaw from getting out of slot H after having been drawnup into position by screw I.

Another slot, K, is also formed or cut out in bar E, in which screw Islides back and forth. Said slot is made just long enough to allow theforward end L of jaw G to strike bar E at M, and the end N of said jaw Gto slide to the end of bar E, being stopped at that point by screw Istriking in the end of said slot.

may be obtained to securely hold it in position.

The forward end P of spring 0 is bent down into slot R (see Fig. 4) forthe purpose of keeping it in its proper position.

A hub or projection, Q, is formed upon sliding jaw G, by means of whichthe operative, by grasping bar E with the hand and fingers, and placingthe thumb over said hub or projection, and moving the thumb back andforth, may conveniently operate jaw G in measuring the diameter of abody.

Bar Eis marked off into inches, and sliding jaw G is marked with twolines an inch apart and subdivided into fractions of an inch, asdesired, said marks on bar E and jaw G being arranged, relative to eachother, as represented in Fig. 2 of the drawings, so that when the jawsare opened or thrown apart by sliding back jaw G, the distance betweenthem is indicated by said lines and figures, thus obviating thenecessity of using a rule.

It will be seen from the accompanying drawings and foregoing descriptionthat calipers thus constructed and arranged are strong and durable, andvery convenient to operate; and by making the jaws circular in form, asrepresented, any diameter embraced within their limits may be measured,whether square, irregular in form, or oval-shaped, with equal facility.

Having described my improvements in calipers, what I claim therein asnew and of my invention, and desire to secure by Letters Patent, is--The combination, with the fixed slotted bar or arm E and its circularjaw F, of the sliding part, upon which circular jaw G and hub orprojection Q are formed, adjusting thumbscrew I, and adjustablespring-plate 0, substantially as and for the purposes set forth.

' HIRAM O. WIGHT.

Witnesses:

ALBERT A. BARKER, EDWIN E. MOORE.

